The present invention relates to the field of lawn mowers and the like, and provides a power-assist mechanism that makes it easy to start the engine of a lawn mower.
Conventional lawn mowers are powered either by electric motors or by gasoline-fueled internal combustion engines. Electric-powered lawn mowers have not been entirely satisfactory, because they require either a long and unwieldy cord that must be plugged into an electrical outlet while the mower is in use, or, if they can operate without a power cord, their batteries must be frequently recharged. By contrast, gasoline-fueled lawn mowers are self-contained, use relatively small amounts of fuel, and produce relatively large amounts of power for extended periods of time.
The major inconvenience of a gasoline-fueled lawn mower arises in starting the engine. Due to the inherent properties of an internal combustion engine, the engine cannot be started unless it is already turning, so that the cylinder(s) and valve(s) are in motion. The conventional starting mechanism on a mower of the prior art includes a pull rope, which is connected to the crankshaft of the engine, and which is manually pulled to start the engine. The rope is typically provided with a retraction mechanism so that after it is pulled out, it will become automatically rewound onto a suitable storage device inside the lawn mower housing.
In practice, a pull rope is inconvenient to use. Many lawn mower motors have only one cylinder and one spark plug, and if the engine is not tuned optimally, the engine may not start on the first try. Indeed, several attempts to start the engine are often required, before the engine finally starts. With a pull rope, it is necessary to exert considerable force to pull the rope out swiftly but smoothly, and this operation becomes especially inconvenient when it must be repeated several times. The difficulty of starting a lawn mower may make it unfeasible for the mower to be used by an elderly or weak person, and may even deter an able-bodied person from using a gasoline-fueled lawn mower.
The present invention solves the above-described problem by providing a gasoline-fueled lawn mower having a power-assisted starting mechanism. The starting mechanism may be provided as a kit for attachment to an existing lawn mower, thereby making a conventional lawn mower much easier to start.